From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 70CDBE7BDA3 for ; Mon, 16 Feb 2026 11:45:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 903356B0005; Mon, 16 Feb 2026 06:45:21 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 87F2A6B0088; Mon, 16 Feb 2026 06:45:21 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 760F96B0089; Mon, 16 Feb 2026 06:45:21 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 5EC2B6B0005 for ; Mon, 16 Feb 2026 06:45:21 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id DEEEA5A95F for ; Mon, 16 Feb 2026 11:45:20 +0000 (UTC) X-FDA: 84450139200.03.2A5EE9B Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf06.hostedemail.com (Postfix) with ESMTP id 0717B180006 for ; Mon, 16 Feb 2026 11:45:18 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=KYu9EeDp; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf06.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1771242319; a=rsa-sha256; cv=none; b=yaBge+0AnVqvlPg4BAfYGFbV/Wo4tP085hgfaZ6JZQiKsf74lWUmVN9rg7rJTJCmUeabP/ G8TqND4MpJW4usQU/9CtfVJRhOMhHg/rlpcAEzRlZp2NJK8q4M9YnW1wnBSk9PAq6kndpq VIFGXDtCyw5EAV9FGB7nGlnNsJ4RIYM= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=KYu9EeDp; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf06.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1771242319; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=R9B6zUAwXDXNbc8BSp99Va8OwvZpoVOSEJppeCrIMfU=; b=pHX9BiCYakmgyvdxIoUJF4S0eeIfq/gLcGgt/2ZRKGAGWrCWqDqM56GyvCQ7ZGvuRZZ8m6 hBAjd4z/b7z7mbCeT1QELi3jy0pEt0IMpYyfVpdgiVg6IxL2qpY2okQvaZeVqbRZc0hmXy vxz41wTaPLsOpPQjIn+jbsZAn0hC1Nk= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id E6C6F42A41; Mon, 16 Feb 2026 11:45:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 493BBC116C6; Mon, 16 Feb 2026 11:45:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771242317; bh=EPqVfuAV2TiFTEwxuoK78ELzQNyTw9nseMJpCxo6KT4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=KYu9EeDpOXCjM7rhlOUAhIivYJ7jNVcrASe1KrczrsfhGfvsjdqSYfqjovteoW21W PNf3kAVonmkH0hWJpYxOhx0/ckxeq52xh4Q8H6UaAF5XjtqkoEhHhc7gBZaec2WSzO y/nq+FIIph473hcMvGqSaeCGyrxF0for5OvTEDyQPwg/t8+i0dFgV5kAkgHmVUCi2G tgF727MnENs+7XTA3sANgD4SnGjqDqRq6qMMGt/nAylakonJu1ouLI0Ur9o6wooWte pptXb5Ca/dnfpOWDM6NFeqyzc5Xzql7ufFddOcp4mivUQq1SJ8mVlUJN/xrakh2C4M OU1A3BwPw0Kjg== Message-ID: Date: Mon, 16 Feb 2026 12:45:13 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm: Add AnonZero accounting for zero-filled anonymous pages To: Kiryl Shutsemau , Wenchao Hao Cc: Andrew Morton , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260214084514.2842745-1-haowenchao22@gmail.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 0717B180006 X-Stat-Signature: u4cjbg9b7gfzqf4uhon3wmnmnkeozux8 X-HE-Tag: 1771242318-29105 X-HE-Meta: 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 HmfkeSwv /72zvQW01YaA/AfofFXuZoFWJ2avtFy+K0cwQuzLTFFyS1g8CPpwgitWKkSU9QqI2orFUMZzQ5mVb8FkMafCn/oXkv36bxmlAMNSoPWVwo6UCSw3f28sW7VYNsOKMkhqosOxUvmm5f892wOjlNFX5SyqUnTRncnstu2WP6DwX/xlvA5m82SpFT9SC3Znr95uwcjNZ7WmzbT2ewz9HxciZGaXuXg2s5d5fNRDlYG5eZ9fsppqaM5A2V7EAf98J1Z8G2Fuu X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2/16/26 12:34, Kiryl Shutsemau wrote: > On Sat, Feb 14, 2026 at 04:45:14PM +0800, Wenchao Hao wrote: >> Add kernel command line option "count_zero_page" to track anonymous pages >> have been allocated and mapped to userspace but zero-filled. >> >> This feature is mainly used to debug large folio mechanism, which >> pre-allocates and map more pages than actually needed, leading to memory >> waste from unaccessed pages. >> >> Export the result in /proc/pid/smaps as "AnonZero" field. > > I expect it to slowdown /proc/pid/smaps read substantially. I don't > think this line in smaps worth it. > That's why it's enabled through a command line parameter. -- Cheers, David